Piston construction



Oct. 15, 1935.

v. R. JOHNSON 2,017,662

PISTON CONSTRUCTION Filed March 5, 1934 ATTORNEYS.

Patented Oct. 15, 1935 T F Fi Q E PISTON CONSTRUCTION Application March 5, 1934, Serial No. 713,984

5 Claims.

This invention relates to pistons for internal combustion engines.

The principal object of the invention is to provide an improved piston construction for internal combustion engines.

Another object is to provide means for preventing piston slap in the operation of an internal combustion engine.

A further object is to make provision for taking upclearanoe due to wear between the wrist pin and the bearings therefor which are secured to the piston.

Another object is to provide a composite piston construction in which integral piston head and skirt portions are detachably securcd to the wrist pin bearings so that the piston may be detached and removed from the head end of the cylinder of an internal combustion engine.

A further object is to minimize oil pumping, leakage by the piston, and wear of cylinder walls.

Still another object is to provide a piston adapted to function efliciently in worn or out-oiround cylinders, thus obviating the necessity of reboring cylinders.

Other objects, features and advantages will become apparent from the following description and appended claims.

For the purpose of illustrating the genus of the invention, a typical concrete embodiment thereof is shown in the accompanying drawing, in which:

Figure l is a side elevation, with parts broken away, of a piston constructed in accordance with the principles of the present invention;

Fig. 2 is a central, vertical section taken on the line 2 2 of Fig. 1, certain elements being shown partly in elevation;

Fig. 3 is a horizontal section taken on the line 3-3 of Fig. l, and

Fig. 4 is a perspective detail ci a part shown in Figs. 2 and 3.

Referring to the drawing, the numeral I0 designates .a piston comprising head and skirt portions Il and I2. Ring grooves I3 are provided in the outer peripheral walls of the skirt portion adjacent the head II for the reception and compression of oil rings I4.

The skirt portion I2 is further provided with a pair of integral annularly directed strips I5 and I6 severed therefrom except at one end, as indicated at IS. The strips i5 and It are severed more than half way around the piston leaving unsevered portions on diametrically opposite sides of the piston so that both the ends l 8 xed to the piston skirt and the free ends I9 of the strip portions cross or overlap with respect to the longitudinal dimension of the piston.

The strip portions I 5 and I 6 are expanded outwardly from the skirt portion I2 of the piston by leaf or straw spring members 20 engaging the =5 inner surfaces of the strip member throughout practically their entire length. The annularly directed strip portions I5 and I6 of the piston skirt are arranged one above and the other below the axis of thewrist pin 23 employed for pivotally l0 connecting the piston to thev connecting rod 24. The details of the mechanism for connecting the wrist pin to the piston will be described at alater point. By arranging the strip portions I5 and l5 at approximately equal distances above and be- 15 low the axis of the wrist pin these strip members, expanded outwardly by the spring elements 20, will resiliently engage the walls of a cylinder in which the piston is adapted to reciprocate and prevent piston slap during operation of an in- 20,

ternal combustion engine. The strip members will also aid 1n preventing the passage of gases or fuel between the piston and the cylinder walls and will prevent pumping of oil by the piston.

The wrist pin 23 ls journaled for rotation in a 25 pair of bearing members 26 and 2l each comprising an upper bearing half 30 and a lower bearing half 3i with the upper and lower bearing halves of each bearing member detachably connected by securing bolts and nuts 33. Shims 34 are re- 30 movably interposed between the upper and lower bearing vhalves to take up clearance between the wrist pin and the bearing members therefor as these elements Wear during operation. An integral T-shaped head 35 is provided on the up- 35 per portion of each of the bearing halves 30 and longitudinally directed threaded openings 36 are provided in the head portions for the reception of bolts 31 projected through openings 40, complementary with the opening 36, for securing the o bearing members to the piston head Il. Gasket members 4l are preferably disposed about the securing bolts 3l between the heads thereof and the upper surface of the piston Ill to prevent leakage to the piston head. 'I'he heads of the securing 5 bolts 31 are preferably provided with transverse openings 42 through which a loop of wire 43 may be passed and the ends thereof twisted together to prevent rotation of the securing bolts and loosening of the connection between the piston head and wrist pin bearing member. The securing bolt and nut assemblies 33 for adjustably con-` necting the upper and lower bearing halves 30 and 3| -may also be provided with locking means such as cotter pins 46and lock washers 4l to prevent 55 loosening of the connection between the Wrist pin bearing members and the wrist pin. 'Ihe upper end of thev connecting rod 24 is in the form of a small end bearing 50 adapted to receive the central portion of the wrist pin 23, and the adjacent portion of the connecting rod is split as indicated at 5| so that a transversely disposed tightening bolt 52 can be locked by means of a split washer 53 to clamp the small end bearing of the connecting rod to the wrist pin. An upwardly projecting boss 5d is provided on the upper surface of. the piston head I I and may be manually engaged to withdraw the piston I out of engagement with the wrist pin bearings 21 and 26 after the securing bolts 31 have been removed.

By virtue of the detachable connection between the piston I0 and the wrist pin bearings 26 and 21, the pistons can be removed from the cylinder simply by removing the cylinder head and then removing the securing bolts 31. This facilitates the replacement of the compression and oil rings I4 by simply removing the cylinder head rather than removing the oil pan of the engine and disconnecting the crankshaft bearings. It is also noted that in the present construction the annularly directed strip members I and I5 are composed of the same material as the piston, preferably of aluminum composition, so that they will cause very little wear of the cylinder walls and in conjunction with springs will take care of any Wear -of the cylinder walls which has previously occurred whether the cylinder walls are out of round or not.

As many changes could be made to the above described construction and many apparently widely diiferent embodiments of this invention could bemade without departing from the spirit thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A piston comprising head and skirt portions, said skirt portion having spaced, integral and annularly directed strip portions severed therefrom except vat one end of each strip portion, said strip portions being located at intermediate zones of said skirt portion and extending in opposite directions more than half way around the periphery of said skirt portion, and spring means engaging the inner surfaces of said skirt and strip yportions for expanding the latter radially outwardly with respect to the skirt portion.

2. A piston including head and skirt portions, said skirt portion including integral annularly directed strip portions each extending more than half way around the piston and severed except at one end thereof from the piston, said strip portions being located at intermediate Zones of the skirt portion, and resilient means engaging the 5 inner surfaces of the strip portions throughout practically their entire lengths for expanding the strip portions outwardly with respect to the remainder of the skirt portion.

3. A piston including head and skirt portions, said skirt portion including annularly directed strip portions each extending more than half way around the piston and severed except at one end thereof from the piston, said strip portions being located at intermediate zones of the skirt portion, and leaf springs e'ach engaging the inner surface of a strip portion throughout practically its entire length for expanding the strip portion outwardly with respect to the remainder of the skirt portion.

4. In combination with a piston including head and skirt portions, a wrist pin, a pair of separate wrist pin bearing members each Acomprising bearing halves and means for adjustably securing said bearing halves around said wrist pin, and means for detachably securing said bearing members to the head portion of said piston, said second-named securing means being accessible from the head end of said piston and said separate bearing members being accessible from the same direction after the rst-named securing means and the piston are removed, said wrist pin and bearing members being so constructed and arranged that each bearing member may be removed from the wrist pin without dis-assembling the bearing halves `and without moving the wrist pin or bearing members beyond the lateral limits of the space normally occupied by the piston.

5. in combination with a piston including head and skirt portions, a wrist pin, a connecting rod including a wrist pin engaging end and means for adjustably clamping said wrist pin against relative movement within such engaging end, a pair of Wrist pin bearing members each comprising bearing halves and means for adjustably securing said bearing halves around said wrist pin, and means for detachably securing said .bearing members to the head portion of vsaid piston, said second-named securing means being accessible from the head end of said piston and said adjustable clamping means and said first-named securing means being accessible from the same direction after the first-named securing means and piston are removed.

VIKRGIL R. JOHNSON. 55 

